Harvest for the world
Energy harvesting has traditionally been associated with small wireless devices, but wich many potential applications, power sourcing and conversion companies are looking further afield.
At the end of July, representatives from 30 countries will convene to discuss the latest developments in the field of monitoring buildings and structure. Among the topics at the Structural Health Monitoring og Intelligent Infrastructures (SHMII) conference will be 'Intelligent' sensors and wireless sensor networks. With the EU's target of reducing energy consumption by 20% by 2020, conferences such as these will become crucial. And the term 'energy harvesting' will be on the lips of most design engineers.
There are four types of energy harvesting - solar, vibration, heat and motion. While some are more established than others, the solutions often complement one and another, depending on the application[...]
EnOcean has been working with thermal energy for four years. Andreas Schneider, EnOcean's executive vp, explained: "We are developing a dc/dc converter that produces 20mV, which we boost to 3 to 5V. In a building it is powered from temperature gauges, water and air, so it can adjust itself accordingly, even if nobody is in the building."[...] EnOceans research on rotation - using energy from body movement - has resulted in its Eco100 energy module. the kinetic energy created by physically pressing the button means it can be used to power radio modules. The energy output at every actuation of the spring is sufficient to transmit three rf sub telegrams - energy pulses sent to remote sensors which continuously monitor for signals. A typical application could be automatic stairwell lighting, where a light is switched on manually and switches off after a specified time.
Some 100,000 buildings are equipped with EnOcean's wireless light switch and the company is now working an a fully automised production line to access the high volume market.
EnOcean has already established its EnOcean Alliance – a group of independent companies working together to establish a wireless standard for sustainable buildings. Schneider explained: "We need to educate architects and specifiers and create an ecosystem of companies all working to the same standard. They all have to deliver interoperable systems and as systems become ever more complex, there has to be a regulation and international legislation on sustainable buildings."
Conferences such as the SHMII symposium are good starting points for design engineers to network with international scientists, enterprisers and researchers; and to discuss the advances in smart sensors, wireless sensor networks and signal acquisition. But the EU's energy consumption reduction directive is fast approaching – and to establish fully integrated and interchangeable systems within 11 years could be a close call. "Energy harvesting is a super, low cost way to create power," concluded Freeland. "As the volume of innovations increases, it will revolutionise our understanding and appreciation of sourcing energy. And it can't come too soon for me."
(Source: New Electronics, 14.07.2009)
